Field of the Invention
The present invention relates generally to special effects lighting, and more particularly to an electronic generator for generating a highly realistic flickering light which has adjustable brightness, flicker rate, and flicker level to accurately simulate, a variety of lighting effects such as fire, reflections from natural sources, and light from man-made sources.
One of the goals in making motion pictures is to have the filmed sequences appear as realistic as possible. In the accomplishment of this goal, a wide variety of special effects are necessary, and the field of special effects has become both a highly specialized profession and an exceedingly complex field. One of the subspecialities of special effects is special lighting effects, in which the effects crew is called upon to produce a wide variety of lighting effects which must appear on film to actually be various types of desired lighting.
One type of lighting which must be frequently simulated is flickering light, such as that generated by fire and other naturally flickering light sources. Examples of such sources include light reflected from the surface of water and light flickering through trees which are moving in the wind. Other types of flickering light called for include simulating flickering light from man-made sources such as motion picture projection and television screens.
In the production of motion pictures, television programs, or live theater productions, such lighting must appear to accurately simulate the desired light source to make a scene appear realistic. During the course of such productions, the level of general lighting used is quite intense, and as such the general lighting would overcome light generated by the natural flickering light sources mentioned above. Therefore, the flickering light source used to simulate the desired light must be more intense than the general lighting used.
Applications aside from motion picture special effects lighting include ornamental lighting where a flickering firelight effect is desired. Low power capacity flicker effect generators can find potential use in homes, restaurants, malls, etc. for Christmas tree lighting, chandeliers, exterior lighting, etc.
As might be expected , the art teaches a number of simulated flickering light sources. Most of these references utilize a common element, which is the movement of a mechanical apparatus to randomly diffuse light from a light source. Examples of such devices are found in McCormick U.S. Pat. No. 1,514,552, in Best U.S. Pat. No. 1,775,885, in Nielson et al U.S. Pat. No. 3,526,984, and in Plambeck et al. U.S. Pat. No. 4,026,554.
The McCormick reference teaches an apparatus used in a novelty display in which a forest fire is simulated. The Best device illustrated an apparatus which simulates a solid fuel fire in an advertising sign. The Nielson et al. and the Plambeck et al. references both teach devices used to simulate burning logs in a fireplace. All of these mechanical devices are used to produce a low level flickering light, and would be unsuitable for use to produce the effect contemplated by the present invention.
Another approach taken to produce a flickering light effect is the use of a valve to modulate a gas fire. This technique is shown in Poling et al. U.S. Pat. No. 3,723,046. Such a device will produce a flickering fire, but the effect has the disadvantage that it is not sufficiently bright for use in the motion picture or television industry. In addition, the use of a live flame carries with it the hazards and dangers of fire, the use of which in a sound stage may better be avoided.
Rather than use such devices, the motion picture and television industry has largely relied on the use of manual, mechanical techniques to produce flicker lighting effects. Such techniques include waving objects in front of a lighting source, using mechanical objects in front of a lighting source, or using a manually operated reflector in conjunction with a lighting source. Such techniques have the disadvantages of being labor intensive, and, even worse, of not producing a light display which appears random in nature.
An electronic device has also been used, with the device using a noise generating diode or other electronic means of producing a random or pseudorandom sequence which may be used to drive a light in a flickering manner. Such devices have virtually no capability for adjustment, with the light output typically alternating between 30% and 100% of maximum output. No control over any of the characteristics of the light or the flicker is available, with the effect not appearing to duplicate as closely as desirable the flickering light source desired.
It is accordingly the primary objective of the present invention that it provide an apparatus for controlling a light and causing it to flicker in an extremely realistic fashion. The flicker must be random in appearance and must drive the light to a number of random light levels rather than the two levels used by known devices. In addition, an improved flicker controlling device must operate fully automatically, with its operation continuing with no other user intervention being required once it is set up.
In addition, it is an objective that the distinctiveness of the flicker effect be capable of precise control, so that the exact nature of the flicker may be controlled to a high degree. As such, the intensity of both the maximum amount of light generated and the degree of flicker should be subject to a highly precise level of control. The device should also retain a high degree of ease of adjustment, making the setup of different flicker effects easy and quick to accomplish.
It is a further objective of the present invention that the device be compact in size, and that it be capable of operation on common line voltage. It should desirably be inexpensive of construction to afford it an economic advantage in competing with currently used manual techniques. It should also be durable and long lasting, to make a well rounded product. It is also an objective that all of the aforesaid advantages and objectives be achieved without incurring any substantial relative disadvantage.